A. Technical Field of the Invention
The present invention relates to methods and apparatuses for using, cleaning, and maintaining electrical heat sources and lighters useful in electrical smoking systems or the like.
B. Discussion of the Related Art
Previously known conventional lit cigarettes deliver flavor and aroma to the user as a result of combustion of tobacco. A mass of combustible material, primarily tobacco, is oxidized as the result of applied heat with typical combustion temperatures in a conventional cigarette being in excess of 800.degree. C. during puffing.
Heat is drawn through an adjacent mass of tobacco by drawing on the mouth end. During this heating, inefficient oxidation of the combustible material takes place and yields various distillation and pyrolysis products. As these products are drawn through the body of the smoking device toward the mouth of the user, they cool and condense to form the aerosol which gives the consumer the flavor and aroma associated with smoking.
Conventional lit cigarettes have various perceived drawbacks associated with them. Among them is the production of sidestream smoke during smoldering between puffs, which may be objectionable to some non-smokers. Also, once lit, they must be fully consumed or be discarded. Relighting a conventional cigarette is possible but is usually an unattractive prospect for subjective reasons (flavor, taste, odor) to a discerning smoker.
Prior alternatives to the more conventional lit cigarettes include those in which the combustible material itself does not directly provide the flavorants to the aerosol inhaled by the smoker. In these lit cigarettes, a combustible heating element, typically carbonaceous in nature, is combusted to heat air as it is drawn over the heating element and through a zone which contains heat-activated elements that release a flavored aerosol. While this type of lit cigarette produces little or no sidestream smoke, it still generates products of combustion, and once lit it is not adapted to be snuffed for future use in the conventional sense.
In both the more conventional lit cigarettes and lit carbon element heated cigarettes described above combustion takes place during their use. This process naturally gives rise to many by-products as the combusted material breaks down and interacts with the surrounding atmosphere.
Several proposals have been advanced which significantly reduce undesired sidestream smoke while permitting the smoker to suspend smoking of the article for a desired period and then to resume smoking. Commonly assigned U.S. Pat. Nos. 5,093,894; 5,225,498; 5,060,671 and 5,095,921 disclose various electrical resistive heating elements and flavor generating systems which significantly reduce sidestream smoke while permitting the smoker to selectively suspend and reinitiate smoking.
U.S. Pat. No. 5,388,594, issued Feb. 14, 1995, entitled "Electrical Smoking System for Delivering Flavors and Method for Making Same"; U.S. Pat. No. 5,499,636, issued Mar. 19, 1996, entitled "Cigarette for Electrical Smoking System"; U.S. patent application Ser. No. 08/380,718, filed Jan. 30, 1995, entitled "Electrical Smoking System for Delivering Flavors and Method for Making Same" (Attorney Docket No. PM 1697 CON/DIV1); and U.S. patent application Ser. No. 08/426,165, filed Apr. 20, 1995, entitled "Heater for Use in an Electrical Smoking System" (Atty. Docket No. PM 1768) each describe an electrical smoking system including novel electrically powered lighters and novel cigarettes that are adapted to cooperate with the lighters, and each is incorporated herein by reference.
The preferred embodiment of the lighter of U.S. Pat. No. 5,388,594 includes a plurality of metallic heaters disposed in a configuration that slidingly receives a tobacco rod portion of the cigarette. One of the many advantages of such smoking systems is the reusability of the lighter for numerous cigarettes.
As these novel cigarettes are heated by the firing of heaters, aerosol is generated for smoking by the smoker. Some portion of the generated aerosol is not delivered to the smoker and may tend to condense and form condensates on the relatively cooler individual heaters, the heater fixture, electrical connections, electronic components and other components and structures located within the cigarette-receiving cavity and/or subject to contact with the generated aerosol. In addition, portions of the cigarette, especially portions which have been heated and therefore thermally weakened, may cling to surfaces, especially to individual heaters, after the cigarette is removed due to tight tolerances.
Such condensation and/or cigarette remnants, especially if permitted to accumulate, can alter the subjective taste of subsequent cigarettes; can block required airflow passages, especially the passageways communicating with any puff sensitive pressure drop sensor and/or with outside ambient air; can damage sensitive electronic and electrical components; and can result in protrusions, snags, etc. which could adversely affect insertion, registration and removal of cigarettes relative to the heater fixture.
Though not desiring to be bound by theory, it is believed that the condensation is the result of the flow pattern and pressure gradient of ambient air drawn through the cigarette and the current designs of the heater assemblies. The heating of the cigarette tobacco produces aerosols which are then cooled to result in condensation on the surfaces of relatively cooler components.
U.S. Pat. No. 5,388,594, issued Feb. 14, 1995 entitled "Electrical Smoking System for Delivering Flavors and Method for Making Same", and U.S. patent application Ser. No. 08/380,718, filed Jan. 30, 1995 entitled "Electrical Smoking System for Delivering Flavors and Method for Making Same", which are hereby incorporated by reference in their entireties, disclose a heater sleeve which surrounds the cylindrical heater assembly and is exposed to residual aerosols to protect an outer air channel sleeve.
As described, this heater sleeve is discarded after a certain interval, e.g. 30-60 cigarettes, and replaced with a new heater sleeve, necessitating a potentially time consuming and/or inconvenient replacement procedure by the smoker. Also, this removal of a used sleeve and installation of a new sleeve could potentially damage the cigarette heater assembly, which may be delicate.
In addition, it is desirable to couple any cleaning of the electrical lighter with other routine maintenance procedures such as recharging of lighter batteries. For example, it may be desired to perform both cleaning and recharging on a daily basis, preferably substantially contemporaneously. Also, it may be desirable to alert the smoker of the necessity of these functions and/or to establish these functions as prerequisites to operation of the lighter.
Also, it is desirable to degrade any cleaning by-products for aesthetic reasons.